[2] He started his education in a school in Krasnystaw but when he was thirteen years old he was sent to study abroad; from 1555 to 1559 he was a page at the royal court in Paris.

[8] He was a colleague of Mikołaj Sienicki and Hieronim Ossolinski, and with them he was one of the leaders of a faction of the lesser and middle nobility (szlachta) in the Commonwealth, whose goal was the reform the country – the execution movement – preserving the unique constitutional and parliamentary government of the Commonwealth with the dominant role of poorer nobility (Golden Freedom).

[15] He also published a pamphlet praising the new king, and thus suffered a loss of face when Henry secretly abandoned Poland and returned to France.

[15] During the following 1575 election he was a vocal enemy of the Habsburg dynasty and its candidate, and this anti-Habsburg stance, resounding among the lesser nobility, helped him regain his popularity.

[9][15] For the king, Zamoyski championed the case of a Polish candidate, which ended up in the marriage of Anna Jagiellon with the anti-Habsburg Stephen Bathory of Transylvania.

[27] Though Zamoyski failed to capture Pskov, he drained the Russian resources, and the ongoing siege was a major reason for the final treaty, which was highly favorable to Poland.

[36] From 1589 Zamoyski, in his role as the hetman, tried to prevent the intensifying Tatar incursions along the Commonwealth's south-eastern border, but with little success.

[37] In order to deal with the recurring disturbances in that region Zamoyski developed a plan to turn Moldavia into a buffer zone between the Commonwealth and the Ottoman Empire; this would lead to a lengthy campaign.

[38] The next year was much more successful, as in Moldavia in 1595 he was victorious in the Battle of Cecora, and helped hospodar Ieremia Movilă (Jeremi Mohyła) gain the throne.

[38] In 1600 he fought against Michael the Brave (Michał Waleczny, Mihai Viteazul), hospodar of Wallachia and the new Prince of Transylvania, who had conquered Moldavia a few months earlier.

[48] In 1600 he recaptured several strongholds from the Swedes and a year later captured Wolmar on 19 December 1601[47] Fellin on 16 May 1602, and Bialy Kamien on 30 September 1602.

[49] At the Sejm of 1603 Zamoyski led opposition to the governance reforms proposed by Sigismund; seeing in them intentions of transforming the Commonwealth into an absolute monarchy.

[9][50] Later, he also opposed Sigismund's plans to intervene in the civil war plaguing Muscovy (the Time of Troubles and the Dymitriads).

[54] Leśniewski, ending his recent biography of Zamoyski, concludes that he is a significant, if controversial, figure of Polish Renaissance.

[49][57] In his tactics, he favored sieges, flanking maneuvers, conserving his forces, and the new Western art of fortification and artillery.

[49] The war with Muscovy shown him to be a skilled commander in sieges, and latter events would prove him to be an equally able leader in the open field.

[60] Totaled, his personal and leased lands covered over 17,000 square kilometres (6,600 sq mi), with 23 towns and cities and 816 villages.

[60] In 1589 he succeeded in establishing the Zamoyski Family Fee Tail (ordynacja zamojska), a de facto duchy.

[65] Artists under his patronage included the poets Jan Kochanowski and Szymon Szymonowic, and the writer and historian Joachim Bielski.

[67] In another example, Leśniewski describes how Zamoyski openly demanded rewards following his victory at Byczyna, and tried to include an article favoring him in the Bytom and Będzin treaty.

[68] He further notes, critically, that with raising power and political success Zamoyski begun displaying negative qualities, such as egoism and arrogance.